view
Class AstroKernel

java.lang.Object
  util.PropertyContainer
      util.PropertyResources
          util.PropertyBundles
              view.AstroKernel

All Implemented Interfaces:

Cloneable, Initializable, LocalizedSupplying, PropertySupplying, ResourceSupplying

public abstract class AstroKernel
extends PropertyBundles
implements Initializable

A kernel is used for filtering an image to detect stars. I hope that any kernel one can think of consists of a (quadratic) matrix of floats. Therefore, methods are supported, getAstroKernel(), getSizeX() and getSizeY(). Additionally, for least-square fitting, the quadratic sum of the kernel minus the sum of the kernel squared divided by the kernel size is return in the (abstract) getWeight() method. Note that this latter method is only useful for quadratic kernels. This class is abstract and not an interface to stress the importance that the computation of the kernel via the protected computeAstroKernel() method should always be done directly after the construction phase using the init() method.

This class work together with the Kernel class by invoking toImageKernel() on it.

Nested Class Summary

Nested classes/interfaces inherited from class util.PropertyResources

PropertyResources.URLResource

Field Summary

private float[][]	kernel The kernel matrix.
static String	KEY_CLASS The key mapping to the CommandLaunching class name.

Fields inherited from class util.PropertyBundles

KEY_LOCALECOUNTRY, KEY_LOCALELANGUAGE, KEY_RESOURCEBUNDLES

Fields inherited from class util.PropertyResources

KEY_NOINITONCREATE, localurl, locate, POSTFIX_DIR, POSTFIX_EXT, POSTFIX_FILE, POSTFIX_LIST, POSTFIX_URL, urlset

Fields inherited from class util.PropertyContainer

KEY_LISTSEPARATOR, KEY_MAPKEYVALUECHAR, KEY_MAPSEPARATOR

Fields inherited from interface util.ResourceSupplying

KEY_URLRESOURCES, KEY_URLUSECONFIG, KEY_URLUSECURRENT, KEY_URLUSEHOME

Fields inherited from interface util.PropertySupplying

CONFIG

Constructor Summary

protected

AstroKernel(Map prop) Constructs the kernel.

Method Summary

protected abstract float[][]	computeAstroKernel() Computes the kernel.
static AstroKernel	createAstroKernel(Map prop) Constructs a new kernel instance using the mapping of the KEY_CLASS to the class name to derive the class to instantiate.
float[][]	getAstroKernel() Returns the kernel as a two-dimensional float array.
int	getSizeX() Returns the size of the kernel in x.
int	getSizeY() Returns the size of the kernel in y.
abstract double	getWeight() Returns the weight of the kernel.
void	init() Initializes the kernel.
Kernel	toImageKernel() Uses the astro-kernel data to construct a image-kernel, as used in the java.awt.image.Kernel class.

Methods inherited from class util.PropertyBundles

clone, getLocalized, getLocalized, getLocalizedString, getLocalizedString, loadResource

Methods inherited from class util.PropertyResources

createFrom, createFrom, createFrom, getApplet, getAsResources, getLocalClassLoader, getPropertiesToKey, getPropertiesToKey, getResource, getResourceAsStream, getResourceFromKey, getResources, keyCreate, keyCreate, reload, setApplet

Methods inherited from class util.PropertyContainer

augment, augment, augment, defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsEnums, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, isNew, parseObject, reload, removeProperty, rescanned, setObject, setProperties, setProperty, stringProperties, toString

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface util.ResourceSupplying

getResource, getResourceAsStream, getResources

Methods inherited from interface util.PropertySupplying

defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, parseObject, removeProperty, setObject, setProperty, stringProperties

Field Detail

KEY_CLASS

public static final String KEY_CLASS

The key mapping to the CommandLaunching class name.

See Also:

Constant Field Values

kernel

private float[][] kernel

The kernel matrix. It is stored as a two-dimensional float array.

Constructor Detail

AstroKernel

protected AstroKernel(Map prop)

Constructs the kernel. It is important to compute the kernel in the construction phase to have it ready for calculation. Therefore, the constructor calls the computeAstroKernel() method. To allow concrete subclasses to carry some properties, a map can be included in the construction phase.

Method Detail

init

public void init()

Initializes the kernel. This method should be called right after construction, which is ensured if the factory method createAstroKernel(java.util.Map) is used to build a kernel.

Specified by:

init in interface Initializable

Overrides:

init in class PropertyResources

getAstroKernel

public float[][] getAstroKernel()

Returns the kernel as a two-dimensional float array.

toImageKernel

public Kernel toImageKernel()

Uses the astro-kernel data to construct a image-kernel, as used in the java.awt.image.Kernel class.

getSizeX

public int getSizeX()

Returns the size of the kernel in x. This method returns the length of the first kernel array.

getSizeY

public int getSizeY()

Returns the size of the kernel in y. This method returns the length of the second kernel array.

getWeight

public abstract double getWeight()

Returns the weight of the kernel. This is defined for quadratic kernels only and is the sum of the kernel-squared minus the squared sum of the kernel, the latter divided by the kernel size.

computeAstroKernel

protected abstract float[][] computeAstroKernel()

Computes the kernel. This method is called in the init() method, i.e. right after the construction of the kernel.

createAstroKernel

public static final AstroKernel createAstroKernel(Map prop)

Constructs a new kernel instance using the mapping of the KEY_CLASS to the class name to derive the class to instantiate. If this property is defined, a new AstroKernel instance with the stated class name is created, the supplied properties used as an argument in the constructor. As all kernels are Initializable, the init() method is called immediately after the construction.